study shows that their is no correlation of Iris abnormal pattern consistency with cancer disease. ref(http://edzardernst.com/2013/06/iridology-if-evidence-is-systematically-ignored-lives-are-put-at-risk/ )
you can get data-sets from the authors of already published paper.
one is in german
Recently did not find anyone working on this domain.
Best way to get related datasets is to initially find some survey papers related to that their might be links to related datasets